The prior art encompasses a wide variety of wheeled carts used by shoppers to transport goods to be purchased, and from a store to the shopper's home. Prior to the advent of the modern supermarket, shopping had to be done on a daily basis and shopping carts were relatively small. A convention prior-art shopping cart used for daily shopping purposes was known to consist of two wheels connected to a collapsible shopping basket having a handle. The shopper used the basket both when selecting items within a store, and for transporting the goods from the store to the home, frequently by way of public transportation. With the advent of the supermarket, daily shopping became a thing of the past and shopping carts became considerably larger. A typical modern shopping cart comprises a mesh (metal or plastic) main basket having two fixed rear wheels, and two front caster wheels propelled by way of a rearwardly positioned handle. In Europe, shopping tends to be more or less a daily or other-day affair, and wheeled shopping carts are still relatively small, perhaps having a volume of only four cubic feet. Carts of this type may be similar to the prior-art two-wheeled cart, or may more conventionally comprise a four-wheeled cart similar to the large, American-style cart but with a shallower basket. In the smaller European design, the basket frequently is located approximately at waist height and may be tipped up so that the shopping carts may nest with one another in a compact fashion. The American-style cart is typically much larger, having a volume of approximately ten to twelve cubic feet with a very deep, fixed basket. The American-style carts are often also nestable. However, due to the fixed basket, the rear wall of the cart is frequently pivotable about a horizontal axis located adjacent the rearwardly disposed handle to facilitate nesting. A nestable cart is advanced toward the rear end of a docking cart, such that the rear wall of the docking cart pivots upwardly when impacted and the front end of the nestable cart advances into a docked position.
At American-style supermarkets, shoppers are encouraged to nest and dock their own carts at the location of the store. Thus nested carts may be ten or fifteen carts deep at times before a customer removes a nested cart from its docked position at the end of that queue. Particularly with the American-style carts, it is known that a nested cart may become “jammed” or stuck with respect to a previously docked cart. Indeed, significant force may be required to separate the nested cart from its docked counterpart. Should the frictional engagement between the nested cart and the docked cart be significantly large, some shoppers, such as the elderly, children, and the like, may not be able to dislodge the nested cart from the docked cart and assistance may be required. This problem is exacerbated in stores and shopping areas where shopping carts are permitted into the parking lot. In these situations, customers are encouraged to dock their carts with respect to one another in a shopping cart nesting area somewhere within the parking lot. An employee of the store then ventures into the parking lot, and retrieves a long sequence or “train” of shopping carts, sometimes ten or fifteen shopping carts long, and pushes those carts back into the store for selection by a shopper. Sometimes, a store may be slightly uphill from the parking lot nesting island for the carts. In that scenario, the store employee may need to use significant force to push the train of nested carts up the hill into the store. Such a process disadvantageously applies an excessive nesting force to the train of carts, such that once the nested train is deposited adjacent the front of the store, one or more carts may become excessively retained within the train, making it nearly impossible for an average shopper to release the cart. In that event, all the carts ahead of the jammed cart become unusable and significant shopper frustration may occur. It is not unknown for certain shoppers, particularly the elderly, infirm, or small of stature, to avoid shopping at establishments where it is difficult or impossible for those shoppers to retrieve a nested shopping cart, which has become “jammed” in a train of nested, docked carts. As a result, establishments employing nesting islands in parking lots may lose valuable customers due to such frustration.
Some grocery markets in Europe now require a shopper to leave a deposit to unleash a shopping cart from a train of nested carts. Typically, two coins must be deposited to unleash a cart from an adjacent cart. When the cart is returned, nested and re-leashed, one coin is returned. The smaller European style carts tend to be more jam resistant because the baskets are folded up out of the way before nesting and only the structurally rigid tubular frames come into engagement. In the larger American style carts, it is the mesh baskets themselves, often deformed which come into engagement and are prone to jamming. Clearly, a U.S. shopper would become extremely frustrated if she paid two coins, unleashed her cart but could not separate it from the queue or train of nested carts should such a system ever come to the Americas.
A need therefore exists for an apparatus that can prevent existing nestable shopping carts from coming into excessive frictional engagement with a docking cart, such that retrieval of the nested cart from a shopping cart train is facilitated.